Keep in mind that the noise from the motor and the noise from case airflow are two entirely different things. The dBA ratings on fans account for only the noise of the fan itself (i.e. the motor), and not the noise of airflow through the case. That's why you can measure the noise of a PC with a 40dB fan (even if its the only fan in the case)...and the actual noise level is much much higher. The case, case material, and case airflow design all impact the level of noise you hear as the result of airflow.
Be sure to use rubber grommets on all fans. The noise from a fan motor can resonate through your case, increasing perceived noise level by a signficant amount beyond that rated for the fan alone; this can be particularly bad/noticeable with aluminum cases. Rubber grommets serve to reduce/eliminate this issue. This applies to the heatsink as well; I found that using a L1A 80mm fan on an AX7 heatsink without the rubber grommets produced at least twice as much noise (to my ears) as the same fan mounted with the included rubber grommets. I use rubber grommets with the fan in my power supply, my case fans, and the fan on my heatsink.
A case with two L1A 120mm fans at 5 volts, or four 80mm L1A fans at 7 volts, should be roughly silent when used with rubber grommets, although this will depend in part on your case's material and airflow design. For info on how to 7volt your fans (which I advise for everything except the cpu fan) can be found at
www.7volts.com.
> I've tried Panaflo L1As, but they weren't strong enough. I just recently tried a
> Thermaltake 37cfm that claims to be 30dBA, but is definitely lying, because it's louder than the Delta.
Other than Papst, the Panflo is about as good as they come as far as noise/CFM. There are other fans that offer comparable or slightly better performance, but I doubt you would notice the difference. And yes, there are a number of vendors that advertise superior noise levels and airflow to the Panaflos, but they generally don't deliver. Panaflo is relatively conservative (or honest?) in their claims, whereas as few other vendors (like PC Power and Cooling) are not.
If you'd replace your Coolermaster HSF with an Alpha PAL8045, you'd find the 80mm L1A (21dB) to be sufficient to cool your Athlon. The 19dB Papst fan also works well with the PAL8045. Combine that heatsink and fan with a 80mm L1A at 7 volts in your power supply, plus two L1A's at 7 volts in your case (with rubber grommets), and you should find yourself with a very low noise case. Of course, you'll also need to use rubber grommets with your hard drive and replace the active cooling on the Radeon with a large passive heatsink. Should you do all that, you'll probably find the Maxtor D740X to be the main source of noise in your case, which you may decide to replace with a much less noisy Seagate Barracuda IV.
